1. Field of the Invention
The present invention relates to a power storage device capable of being charged without receiving power from commercial power.
2. Description of the Related Art
Electronic devices such as a cellular phone, a mobile computer, a digital camera, and a digital audio player have been advanced to be downsized, and a large variety of products have been shipped to the market. In such portable electronic devices, a secondary battery as a power supply for driving is incorporated. As a secondary battery, a lithium-ion battery, a nickel-hydrogen battery, or the like is used. The secondary battery is charged by receiving power from commercial power. For example, a user connects an AC adapter to a household plug socket deposited in each home to charge the secondary battery.
Although portable electronic devices are convenient, the hour of use is restricted by the capacity of the secondary battery. The user of the electronic device needs to pay attention to remaining battery level of the secondary battery and to be always conscious of the charging time. Further, the charging plugs of the electronic devices are different for each device or for each model. Therefore, many AC adapters are required to be possessed.
In contrast, a power storage device is disclosed, in which a permanent magnet is moved back and forth in a slide where a coil is rolled to generate electromagnetic induced electromotive force, whereby the power storage device is charged (for example, Reference 1: Japanese Published Patent Application No. 2006-149163 (FIGS. 1, and p.4)). According to this device, power storage devices are considered to be capable of being charged without receiving power from commercial power supply.